I won for the first time several months ago and I'm still amazed at how quickly progression came after that. The next few times you win you may not make it back up with the amulet, but once you do almost every time you make it past level 10 or so you'll make it all the way down and back up again.
Yeah, this game is really just a learning curve. Took me 80+ runs to get a w, and now without challenges I win about 30% of the time.
I've been struggling to get a win with 6 challenges though.
I have been trying to win one game for each class, and it took me forever to win with warrior and have not been able to with mage, but I don't want to skip mage before going to next class.
I did that too, and mage ended up being the last one I won with. Ironically, I think I ended up leaving his staff with magic missile that run because I ended up with a ton of wands, so I could buff all of them at once at will by using my staff.